The Chelsea boss met the former Manchester United defender for a television interview.
During his first spell at Stamford Bridge, Mourinho pulled no punches in revealing what he thought of Sir Alex Ferguson's United side - on more than one occasion.
After moving to west London, the 'Special One' indeed got the better of Ferdinand and his team-mates, winning the Premier League in his first two seasons at the club.
But Ferguson's men had the last laugh as they bounced back stronger and went on to dominate English football once more.
Now, Mourinho is about to embark on his second season at Chelsea... for the second time. But Ferdinand is now at Queens Park Rangers and also spends plenty of his time carrying out media duties.
One of those media duties, it turns out, was to interview Mourinho (!) and one of the first things the Portuguese boss told him was that new signing Cesc Fabregas will take Chelsea's midfield to 'the next dimension.'
“Fabregas is the player we need to modify a little bit the profile of our game, which we need,” the 51-year-old explained. “We want to give the next dimension to our game in midfield and Fabregas is this kind of player which I like to call ‘the 7’, because he’s not the 6 and he’s not the 8.”
“Normally the 7 is the winger, I also call the 7 the guy in midfield who’s not the 6, he’s not the 8. Or he’s a 6 and 8 at the same time. So he’s a 7 and we need him a lot.”
The Blues bought Fabregas, a former Arsenal midfielder, from Barcelona for £27 million this summer.
Mourinho's side will play two more pre-season friendlies - against Ferencvaros and Real Sociedad - before beginning their Premier League campaign at Burnley next weekend.
How important will Fabregas be for Chelsea this term?